Recent evidence suggests that the prevalence of cigarette smoking among individuals living with HIV/AIDS is dramatically higher than the prevalence in the general population. Given the association of smoking with numerous adverse HIV-related health outcomes (e.g., malignancies, cardiovascular disease, pulmonary infections, and oral diseases), innovative smoking cessation interventions targeting this growing population are greatly needed. The purpose of the proposed project is to compare two such interventions. A two-group randomized clinical trial will be used to compare smoking abstinence rates among a group (n=250) receiving a cellular phone intervention (CPI) to a group (n=250) receiving a recommended standard of care intervention (RSOC). All participants will be drawn from the low income, multiethnic patient population of a large inner city HIV/AIDS treatment center. The RSOC group will receive brief physician advice to quit, written materials, and a 10-week supply of nicotine replacement therapy (NRT) patches. This standard treatment approach is recommended in the Treating Tobacco Use and Dependence Clinical Practice Guideline and has been shown to be effective with other populations. The CPI group will receive 3-months of proactive smoking cessation counseling delivered via cellular telephone in addition to brief physician advice to quit, written materials, and NRT. Counseling session content of the CPI will be primarily drawn from cognitive-behavioral and motivational interviewing techniques. The primary outcome for this study will be point prevalence smoking abstinence 3-, 6-, and 12-months post scheduled quit day. The specific aims are to: 1) develop the CPI and compare it to a RSOC control group in a randomized clinical trial;and 2) evaluate the role of withdrawal, motivation, risk perception, self-efficacy, coping skills, social support, and negative affect as potential mediators of smoking abstinence. As a secondary exploratory aim, the cost- effectiveness of the two treatments, in terms of costs per treatment per smoker quit, will be compared.